Searching for information, over a network for example, can be time consuming and computationally intensive. A typical search on the Internet could involve several hundred database servers. Denial of service attacks can be frustrating for users and developers of search systems. Denial of service attacks can be implemented in various ways. A denial of service attack can corrupt system hardware and/or software or can interfere with routing information. A denial of service attack also can prevent users from using systems by overloading resources. For example, a search engine can be overloaded if the system is bombarded with requests for information that can not be found. In an attempt to find the requested information, the system searches its entire memory structure, (e.g., disk memory or databases connected to the Internet), each time it is queried. Because the system is busy searching for nonexistent information, the system response time is considerably slowed down. Denial of service attacks also can prevent search systems from responding to additional requests. A user of a search system under a denial of service attack may think the search system itself is faulty. This can lead to reduced use of a provider's product, resulting in reduced revenue and possible tarnish of the provider's good name.